1. Field of the Invention
The present invention relates to a liquid-enclosing type vibration isolating device used for isolating a vibration in supporting a vibration generating body such as a power unit mainly as an automotive engine and the like.
2. Description of the Related Art
A liquid-enclosing type vibration isolating device has been known as a mount for supporting a vibration generating body such as an automotive engine in such a manner as not to transmit a vibration thereof to a vehicle body. In the liquid-enclosing type vibration isolating device, a cylindrical main body metal fitting and a mounting metal fitting respectively fastened to a vibration generating body and a support are connected to each other through a vibration isolating body consisting of a block-like rubber elastic body within the main body metal fitting, a diaphragm consisting of a rubber film is disposed in such a manner as to face the vibration isolating body so that an internal chamber is formed as a liquid-enclosed chamber. The liquid-enclosed chamber is divided into two chambers by a partition so that both chambers are communicated with each other through an orifice. Accordingly, a vibration-damping performance and a vibration-insulation performance can be achieved by a liquid flowing effect between both the chambers due to the orifice and a vibration isolating effect of the vibration isolating body.
In this kind of vibration isolating device, a stopper mechanism is provided for restricting a large vertical displacement of the main body metal fitting which is due to a deformation of the vibration isolating body caused by the vibration.
In the conventional structure employed for the stopper mechanism, a member such as a stabilizer is mounted on the mounting metal fitting and a stopper mechanism in the vertical direction is constituted by a part of said member such as a stabilizer and a projecting portion in a part of the vibration isolating body. This structure has no sufficient support strength as a stopper, so that there has been a risk that the stopper deviates from its operationable position at a time of the large displacement of the main body metal fitting. Accordingly, particularly in recent years, there has been suggested a liquid-enclosing type vibration isolating device of "all around (whole circumference) stopper type", in which the mounting metal fitting is provided with a stopper flange projecting in a radial direction, while a cylindrical stopper metal fitting (i.e., a stabilizer) is fixed to the main body metal fitting with an end portion of the stopper metal fitting being inwardly bent and extended, thereby forming a stopper portion having a contact surface on whole circumference (for example, Japanese Utility Model Application No. 7-189131(1995)).
Here, in the all around stopper type with the cylindrical stopper metal fitting described above, heat is accumulated in the inner portion of the stopper metal fitting to increase an ambient temperature of the vibration isolating body. As a result, there is such a problem in durability of the device that the increased temperature promotes deterioration of a rubber as a material of the vibration isolating body.
Accordingly, it is required for the vibration isolating body made of a rubber elastic member to be placed farthest possible from the engine as a heat source and to avoid interference with the other parts, so that there has been considered as means for meeting the requirement that the mounting metal fitting to which the stopper rubber is attached is set to be at the side of the support such as the chassis.
In this vibration-isolating device, it is required that the mounting metal fitting is able to be securely and stably mounted on the support side. Further, in a mounting operation, it is also required that coming off of the mounting metal fitting and the members constituting the all around or whole circumferential stopper provided in the mounting metal fitting, or the like, is able to be prevented, thereby ensuring good assembling operability and mounting operability and, further, maintaining good performance.